Tolerance and near-tolerance strategies in monkeys and their application to human renal transplantation

Summary: Studies in non-human primates to evaluate tolerance strategies in organ transplantation have led to innovation in human transplantation. The two strategies we have studied in detail in non-human primates are T-cell depletion by anti-CD3 immunotoxin and co-stimulation blockade. Each of these strategies has been extended into early human trials in renal transplantation. The results of these human and non-human primate studies are summarized. Continued progress in better and safer immunosuppressive methods remains closely linked to research using non-human primates. However, there has not been a one-to-one correspondence between efficacy in the primate and efficacy in humans. Rather, principles can be derived from non-human primate studies that can be extended into human trials with the knowledge that regimens will likely differ in humans compared to non-human primates.     

Clinical evaluation of novel buccoadhesive film containing ketorolac in dental and post-oral surgery pain management

Ketorolac tromethamine (KT), a non-steroidal anti-inflammatory drug, was formulated in buccoadhesive film to overcome the limitations in the currently available routes of administration which in sequence will increase patients' compliance. The film was formulated using aqueous solvents by means of two bioadhesive polymers namely: hydroxylpropyl methyl cellulose (HPMC) and Carbopol 934. The prepared film was subjected to investigations for its physical and mechanical properties, swelling behavior, in vitro bioadhesion, and in vitro, in situ and in vivo release. Anti-inflammatory efficacy and analgesic activity of the prepared buccoadhesive film were investigated in rats using the hind-paw oedema test and the hot plate method. The analgesic efficacy and tolerability of a single 30 mg dose of KT formulated into the buccoadhesive film was clinically evaluated using a standard, widely accepted post-oral surgery pain model. In this study, the prepared film has been administrated to dental post-operative patients for relieving pain in dental hospital clinic. Results indicate that the concentration of KT in the oral cavity was maintained above 4.0 microg/ml for a period of at least 6 h. The buccal KT film was excellently tolerated in all patients and no complains of GI side effects were reported. It is concluded from this clinical evaluation that KT formulated into a buccoadhesive film is effective as a potent analgesic in dental and postoperative oral surgery in a single dose of 30 mg with minimal GI side effects.     

Rheological and mucoadhesive characterization of poly(vinylpyrrolidone) hydrogels designed for nasal mucosal drug delivery

Poly(vinylpyrrolidone) (PVP) hydrogels were crosslinked by gamma irradiation to add structure and rigidity, and then rheological and mucoadhesive properties were evaluated. The effects of PVP concentration, radiation dose, and additives, such as poly(ethylene glycol) (PEG) and glycerol, on rheological properties were investigated. In an oscillatory analysis, an increase in polymer concentrations increased the storage modulus (G′) and the loss modulus (G″) but decreased the loss tangent (tan δ < 1). The relationships between G′or G″ and the frequency levelled off at higher frequencies, which is indicative of polymer chain entanglement and network formation. Each of the 6% PVP hydrogels exhibited plastic flow with rheopectic behavior. PVP concentration, radiation dose, and the presence of PEG or glycerol influenced the rheological and mucoadhesive properties of the hydrogels. However, adding acyclovir to the formulation did not have a profound effect on the rheological behavior of the hydrogels. The results suggest that a 3% PVP hydrogel with 1% PEG crosslinked with 20 kGy is the most appropriate hydrogel. The results demonstrated the successful complementary application of oscillatory and flow rheometry to characterize and develop a hydrogel for mucosal drug administration.     

Designing an extended release waxy matrix tablet containing nicardipine–hydroxy propyl β cyclodextrin complex

Aim

The current study aimed to prepare a sustained release tablet for a drug which has poor solubility in alkaline medium using complexation with cyclodextrin. Nicardipine hydrochloride (NC) a weak basic drug was chosen as a model drug for this study.

Method

Firstly the most suitable binary system NC-HPβCD was selected in order to improve drug solubility in the intestinal media and then embedding the complexed drug into a plastic matrix, by fusion method, consists of glycerol monostearate (GMS) as an inert waxy substance and polyethylene glycol 4000 (PEG4000) as a channeling agent, after that the final solid dispersion [(NC:HPβCD):GMS:PEG4000] which was prepared at different ratios was mixed with other excipients, avicel PH101, lactose, and talc, to get a tablet owning dissolution profile complying with the FDA and USP requirements for the extended release solid dosage forms.

Results

Infrared spectroscopy (IR), differential scanning colorimetry (DSC), polarized microscopy and X-ray diffractometry proved that the coevaporation technique was effective in preparing amorphous cyclodextrin complexes with NC and trapping of NC within the HPβCD cavity by dissolving both in ethanol and evaporate the solvent using a rotavapor at 65 °C. Dissolution profile of NC enhanced significantly in pH 6.8 from NC:HPβCD inclusion complex prepared by the rotavapor (t-test Student p < 0.05). The release of NC from tablet containing [(NC:HPβCD):GMS:PEG4000] [(1):0.75:0.5] (w/w/w) solid dispersion (F8) was complying with the FDA dissolution requirements for extended release dosage forms, and studying the kinetics of the release showed that the diffusional contribution is the major factor controlling the drug release from that formula.

Conclusion

The prepared waxy matrix tablet containing NC complexes with CD shows promising results as extended release tablets.     

MicroRNA signature in the chemoprevention of functionally-enriched stem and progenitor pools (FESPP) by Active Hexose Correlated Compound (AHCC)

Purpose: Many breast cancer patients use natural compounds in their battle against breast cancer. Active Hexose Correlated Compound (AHCC®) is a cultured mushroom mycelium extract shown to favorably modulate the immune system and alleviate cancer burden. Cancer Stem cells (CSCs) are a subset of highly tumorigenic cancer cells that are thought to be responsible for recurrence. CSCs can be epigenetically regulated by microRNAs (miRNAs). We hypothesized that AHCC may influence CSCs by modulating tumor-suppressor or oncogenic miRNAs. Methods: Functionally-enriched stem and progenitor pools (FESPP) were isolated in the form of mammospheres from MDA-MB-231, MCF-7, and 4T1 cells, exposed to AHCC in both regular and primary culture from Balb/c mice, and analyzed by visual counting and flow cytometry. Cell motility was also observed in MDA-MB-231 cells. Profiling and RT-qPCR were performed to determine AHCC influence on miRNAs in MDA-MB-231 mammospheres. Additionally, Balb/c mice were orally gavaged with AHCC, and tumor growth parameters and miR-335 expression were analyzed. MDA-MB-231 cells were transfected with miR-335 and analyzed by western blot. Results: We demonstrated that AHCC reduced mammosphere growth in three cell lines and in primary culture, prevented cell migration, and upregulated miR-335 expression in MDA-MB-231 cells and mouse tumor samples. Among the differentially regulated miRNAs in CSCs, we focused on tumor suppressor miR-335, known to target extracellular matrix protein Tenascin C (TNC). TNC is involved in CSC immune evasion pathways. In MDA-MB-231, inhibition of miR-335 increased TNC protein expression. Conclusions: These results support that AHCC limits FESPP growth, partly by targeting miRNA pathways.     

Polycyclic Aromatic Hydrocarbons in Indoor Air and Dust in Kuwait: Implications for Sources and Nondietary Human Exposure

This study reports concentration of polycyclic aromatic hydrocarbons (PAHs) in indoor air and dust samples collected from 24 homes in Kuwait. Mean ΣPAHs in indoor air ranged from 1.3 to 16 ng/m³ with a geometric mean of 5.6 ng/m³, whereas the dust concentrations varied over three orders of magnitude, from 3 to 2920 ng/g, with a geometric mean of 165 ng/g. The low-molecular-weight tricyclic and tetracyclic PAHs dominated the air profile constituting ∼70–90 % of the measured compounds, with phenanthrene (51%), fluorene (13 %), fluoranthere (8 %), and pyrene (7 %) being the major contributors. The PAH profile in dust was dominated by the high-molecular-weight PAHs, with three compounds (benzo[a]pyrene, benzo[k]fluoranthene, and benzo[b]fluoranthene) contributing ∼60% of the average ΣPAHs measured in the samples. Indoor-to-outdoor (I/O) ratios for individual compounds were <1 for the majority of compounds, suggesting that there were no significant indoor sources for these compounds in these homes. Using the measured concentrations in air and dust, together with estimates of inhalation and inadvertent dust ingestion rates for children and adults, estimated human nondietary exposure on a BaP_equiv basis were 547 pg/kg body weight/day and 205 pg/kg body weight/day for children and adults, respectively. Exposure from dust ingestion contributes about 42% of nondietary intake of ΣPAHs in children, but only 11% for adults. The threefold difference in exposure estimates between children and adults in this study supports previous reports that children are at greater risk from pollutants that accumulate indoors.     

Anti-IGE therapy in asthma

Immunoglobulin E (IgE) is the hallmark of allergic diseases and asthma. Regulating IgE production has been the focus over several years as an important strategy in the treatment of allergic diseases. Recently, nonanaphylactogenic antihuman IgE antibodies have been under clinical evaluation as a therapeutic agent against atopic disease. In asthmatic subjects, the administration of these monoclonal anti-IgE antibody has been shown to reduce plasma IgE levels, reduce early and late phase allergic responses after allergen provocation, improve symptoms and reduce rescue medication. No serious side effects were reported. Thus, the clinical effectiveness of these medications supports the viability of anti-IgE therapy as a potentially effective treatment option for asthma.     

Effect of bacterial peptidoglycan on erythrocyte death and adhesion to endothelial cells

Peptidoglycans, bacterial wall components, have previously been shown to trigger eryptosis, the suicidal erythrocyte death, characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine exposure at the cell surface. Phosphatidylserine exposing erythrocytes adhere to the vascular wall at least partially by interaction of erythrocytic phosphatidylserine with endothelial CXC chemokine ligand 16 (CXCL16). The present study explored whether peptidoglycan exposure fosters the adhesion of erythrocytes to human umbilical vein endothelial cells (HUVEC). To this end, HUVEC were treated for 48 h with peptidoglycan (10 μg/ml) and CXCL16 abundance determined by confocal microscopy and FACS analysis. Moreover, human erythrocytes were exposed for 48 h to peptidoglycan (10 μg/ml) and phosphatidylserine exposure estimated from binding of fluorescent annexin-V, cell volume from forward scatter in FACS analysis and erythrocyte adhesion to human umbilical vein endothelial cells (HUVEC) from trapping of labeled erythrocytes in a flow chamber. As a result, bacterial peptidoglycan exposure was followed by increased CXCL16 expression in HUVEC as well as erythrocyte shrinkage, phosphatidylserine exposure and adhesion to HUVEC under flow conditions at arterial shear rates. The adhesion was significantly attenuated but not abrogated in the presence of either, erythrocyte phosphatidylserine-coating annexin-V (5 μl/ml) or CXCL16 neutralizing antibody directed against endothelial CXCL16 (4 μg/ml). In conclusion, exposure to peptidoglycan increases endothelial CXCL16 expression and leads to eryptosis followed by phosphatidylserine- and CXCL16-mediated adhesion of eryptotic erythrocytes to vascular endothelial cells.     

Recurrent agnathia–otocephaly caused by DNA replication slippage in PRRX1

Agnathia–otocephaly is a rare craniofacial malformation complex that is caused by de novo heterozygous and biallelic mutations in PRRX1 in two unrelated babies, respectively. We studied the PRRX1 gene in a non‐consanguineous Indonesian female infant who was diagnosed prenatally with severe retrognathia (bilateral Pruzansky type III). Her older affected brother died shortly after birth and had agnathia–otocephaly. A c.266_269dupAAAA frameshift mutation in the poly A tract in PRRX1 was identified in the proband while her father only had an inframe duplication (c.267_269dupAAA) of the adenosine trinucleotide residue. Expression of both mutations in COS7 cells showed loss of function of the frame shift mutation only. Results of SNP genotyping coupled with recurrence of this novel mutation in this family are consistent with a paternally derived germline mosaicism rather than autosomal recessive inheritance as predicted by the family history. Severe retrognathia (bilateral Pruzansky III) and agnathia–otocephaly represent a spectrum of craniofacial malformations in this family. © 2013 Wiley Periodicals, Inc.